Safe syringe

Abstract

A safe syringe having been drawn to a negative pressure status by an inner tube inside the plunge, a grip inserted to the top of the plunge that holds against each other with a catch of the syringe; upon completing the injection, the position of the plunge is changed to release the needle from the syringe, and the grip from the plunge for the negative pressure inside the plunge to fast suck the needle into the inner tube of the plunge, thus to be concealed in the plunge to prevent infection by any one due to accidental sting by the needle.

I claim,  
     
         1 . A safe syringe comprised of a syringe having a proper capacity to accommodate injection contents; a needle at the front end of the syringe to inject the contents, a plunge inserted into one end of the syringe to push the contents towards the needle; wherein, a hole and a catch holder are provided on the front end of the syringe, and a catch to engage the catch holder is provided at the rear end of a needle tip for the needle so to accommodate the needle inside the syringe to facilitate the needle tip to penetrate through the syringe; characterized by that: 
 said inner tube of the plunge having been drawn to a negative pressure status, a grip retained by the needle inserted in the front end of the plunge for the grip at the front end of the plunge to engage with the catch of the needle upon completing the injection when the plunge being pushed down to the bottom of the syringe, then by simply changing the position of the plunge, the needle and the grip respectively disengaged from the syringe and the plunge for the needle to be fast sucked into the inner tube due to presence of negative pressure in the inner tube of the plunge to fully conceal the needle inside the plunge.    
     
     
         2 . A safe syringe as claimed in  claim 1 , wherein, a first engagement area and a first engagement section, and a first slope push area and a first slope push section are provided at where said catch is inserted into the catch holder to firmly engage the catch to the syringe as the first engagement section being close engaged with the first engagement area of the catch; as the catch turns, the first slope push section pushes against the first slope push area for the first engagement section of the catch to retreat the first engagement area of the catch thus to disengage the needle from the syringe; an opening provided at the frond end of the inner tube of the plunge to receive the grip with the other end provided a cover to close the inner tube; said grip being inserted into the inner tube from the end having the cover to close up the opening; the other end of the inner tube being closed to maintain its negative pressure status inside by the cover once the entire plunge being drawn to negative pressure in the inner tube; a second engagement area and a second engagement section, and a second slope push area and a second slope push section respectively provided at where the grip engages the opening for the grip to firmly engage with the plunge and to prevent the grip from being sucked into the inner tube of the plunge as restricted by the engaged second slope push area and section and the tight engagement of the second engagement area and section; the second slope push section of the grip pushing against the second slope push area of the opening as the plunge turns against the grip for the second engagement section of the grip to retreat from the second engagement area of the opening to release the grip from the plunge; the grip continues to turn to disengage its second slope push section from the second slope push area of the opening, thus to free the grip from the opening and immediately sucked into the bottom of the inner tube due to the negative pressure present in the inner tube.  
     
     
         3 . A safe syringe as claimed in  claim 2 , wherein, an insertion of the grip protrudes from the frond end of the plunge, an insertion hole formed at the edge of the catch of the needle to receive the insertion, a first stopper and a second stopper holding against each other respectively provided in the inner circumference of the insertion hole and the outer circumference of the insertion; a first retainer and a second retainer respectively provided at where corresponding to said first and second stoppers holding against to each other; the insertion passing through the insertion hole rotates for the first and the second stopper to hold against each other between the insertion and the insertion hole while the first retainer engages the second retainer for the grip to hold against the catch and for the catch to turn along with the grip.  
     
     
         4 . A safe syringe as claimed in  claim 3 , wherein, a stopper latch is provided for the grip by the side of the second stopper of the insertion at an spacing equal to the width of the first stopper so that once both stopper hold against each other, the stopper latch holds against the other side of the first stopper to hold steady both stoppers, thus to even firmly secure the grip to the needle.  
     
     
         5 . A safe syringe as claimed in  claim 1 , wherein, said catch holder is inserted to the front end inside the plunge with the first engagement area and the first engagement section closed engaged to each other respectively provided on said catch holder and said catch; a first positioning area and a second positioning area respectively provided at where said plunge inserted into the catch holder to position the entire needle at the front end of the syringe as restricted by the engaged first and second positioning areas of the catch holder and syringe and the catch holder being close engaged with the catch; a space formed in the rear of the catch holder for the syringe to accommodate the injection contents while said catch holder prevents from movement as restricted by the first and the second positioning areas; a stop section formed between the needle tip and the catch holder for the needle to firmly secure the needle in position without being affected by the push of the plunge; another space provided between the catch holder and the bottom of the syringe for the catch holder to retreat when subject to push by the plunge; an opening formed at front end of the inner tube of the plunge to receive direct insertion by the grip; a second engagement area and a second engagement section close engaged to each other being respectively provided at where the opening engaged with the grip; the plunge being completely pushed down to the bottom of the syringe upon completing injection for the grip to firmly hold the syringe; the catch holder being pushed into the retreat section as the plunge continues to push down the syringe; the needle remains steady as being restricted by the stopper section while relatively the catch being disengaged from the catch holder to release the needle from the syringe, and the grip at the front end of the plunge retreats to the plunge inner tube as being pushed by the needle to release the opening of the plunge from the grip for both of grip and needle to be sucked into the plunge inner tube due to negative pressure present therein.  
     
     
         6 . A safe syringe as claimed in  claim 5 , wherein, hook and latching hole are respective provided on the front end of the grip and the end of the catch of the needle to firmly secure the grip and the needle as the hook is engaged in the latching hole.  
     
     
         7 . A safe syringe as claimed in  claim 1 , wherein, a groove inserted with leak-proof ring is provided on the outer circumference of the grip and located between the grip and the plunge inner tube to improve air tightness between the grip and the inner tube for the grip to operate being subject to suction by negative pressure to firmly hold against the bottom of the inner tube, thus to secure the needle inside the plunge.  
     
     
         8 . A safe syringe as claimed in  claim 1 , wherein, a piston is inserted on the outer circumference at the front end of the plunge to improve the air tightness between the plunge and the syringe.